Validate Radio Button AngularJS

Question

This seems like it should be fairly easy, but I'm not finding the answer. I have a form where I need to validate that a selection has been made from a radio group. I tried using the 'required' attribute on the radio buttons, but when the form is validated it complains unless all the radio buttons are selected (which is impossible by design).

What is the proper way to validate a radio group selection in AngularJS?

<form name="myForm" ng-submit="submitForm()" ng-controller="ExampleController">
  <input type="radio" ng-model="color" value="red" required>  Red <br/>
  <input type="radio" ng-model="color" value="green" required> Green <br/>
  <input type="radio" ng-model="color" value="blue" required> Blue <br/>
  <tt>color = {{color | json}}</tt><br/>
  <button type="submit">Submit</button>
</form>

Clicking the submit button in the Plnkr shows the behavior.

http://plnkr.co/edit/3qcIbMvJk19OvokcHe2N?p=preview

Solution 1

Try using ng-required="!color". This makes it so that the field is only required when the value is not set. If a value is set, then required is removed and it will pass validation.

<input type="radio" ng-model="color" value="red" ng-required="!color">  Red <br/>
<input type="radio" ng-model="color" value="green" ng-required="!color"> Green <br/>
<input type="radio" ng-model="color" value="blue" ng-required="!color"> Blue <br/>

Here is an updated plunker that demonstrates that the form now validates correctly: http://plnkr.co/edit/EdItU2IIkO1KIsC052Xx?p=preview

Update

e-cloud's answer is simple and doesn't require an additional directive. I suggest everyone use that method if possible. Leaving this answer here as it does provide a working solution and demonstrates the use of the ng-required directive.

Solution 2

I think what you need is to add a name for the radio group, for a radio input need a name to determine which it belongs to, the link below works validation without ng-required(the accepted answer)

<input type="radio" name='group' ng-model="color" value="red" required>  Red <br/>
<input type="radio" name='group' ng-model="color" value="green" required> Green <br/>
<input type="radio" name='group' ng-model="color" value="blue" required> Blue <br/>

http://plnkr.co/edit/LdgAywfC6mu7gL9SxPpC?p=preview

Comments

[Spencer]

ng-required instead of just required does it. Thanks.

[Taryn East]

If you have a new question, please ask it by clicking the Ask Question button. Include a link to this question if it helps provide context.

[jroot]

Sorry, this was supposed to be an alternative solution that works in Firefox (v 33.0). The currently accepted answer didn't work for me.

[Taryn East]

cool, so this is a solution that works? If so, awesome. Possibly just the language in your answer doesn't make that super-obvious :)

[PhiLho]

Works fine, and the name of the group is necessary for correct radio-button working, particularly if you have several groups in a form...

[e-cloud]

@CilliéMalan, i guess it's always working this way. At least from 1.2.

[Robert Hickman]

Something important to note, is that a radio button group is considered valid regardless of an option being selected unless at least one of the radio buttons in a group has the ng-model attribute.

[jamiebarrow]

Another thing to note is that this doesn't fix the issue where one wants to bind on the $touched or $dirty property of ng-model, but there is a workaround (at least for $dirty) where ng-form can be nested and referred to. See similar question here - stackoverflow.com/questions/22181462/…

[Rod Hartzell]

Brilliant! Thank you.

[Ahmed Hasn.]

this solution doesn't work, not even in the provided plnkr demo.

[dmullings]

@ConquerorsHaki It seems to be still working for me. You are allowed to submit the form when a value is selected. What are you seeing?

[Ahmed Hasn.]

exuse me @dmullings I must have confused the plnkrs. It indeed does work like a charm!

[Dev01]

Where is SaintScott's answer? Thanks!

[dmullings]

@TomKrones looks like his name was changed to e-cloud